GDScript: Unexpected behavior of `match` on float variable with integral constants

[resistor]

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Godot version

4.0 stable

System information

macOS 13.2.1

Issue description

When performing a match on a float variable, the match will fail if the match arms are written as integral constants. That is, if the variable contains the value 5.0, a match arm of 5 will fail to match. This is non-obvious behavior for users coming from most other programming languages.

Steps to reproduce

See minimal GDScript snippet

Minimal reproduction project

func test():
	var a: float = 20.0
	match a:
		20:
			print("PASS")
		_:
			print("FAIL")

[dalexeev]

This is intentional. match is more strict than ==. In 3.x the behavior is the same.

[kleonc]

So match's documentation needs to be improved: https://github.com/godotengine/godot-docs/blob/b8eb2d2a6ea4f3abb29ba79f6a99092abdfad95e/tutorials/scripting/gdscript/gdscript_basics.rst#match

It doesn't tell how exactly comparisons are done (e.g. if they're type-strict). Besides that I'm not sure if it's up to date (if / what has changed since it was written).

Also it says:

It's the equivalent of the switch statement found in many other languages

which may lead to confusion like in here (as these are not necessarily equivalent, rather similar).

[resistor]

It seems that, with static typing information, there should at least be a warning for impossible match arms based on types.

[Paladin-Caffeine]

Hi, I noticed the same thing. Match statement and if/elif work differently with numbers, see code below. I think it is necessary to add an explanation to the documentation on match, if/elif and JSON (All number parsed from JSON became float).

var f : float = 8 var i : int = 2 var dictionary = {"some": 5, "random": i, "numbers" : f} var array = [5, i, f]

for n in array.size(): print("> for i in array: ", array[n], " type of: ", typeof(array[n])) if array[n] == 5: print("Is equal to 5") elif array[n] == 2: print("Is equal to 2") elif array[n] == 8: # <-- here we compare float 8 to 8, and it is ok print("Is equal to 8") else: print("The numbers are not equal!")

for n in dictionary: print("> For n dictionary: ", dictionary[n], " type of: ", typeof(dictionary[n])) match dictionary[n]: 5: print("> Wow it's matched to 5") 2: print("> Wow it's matched to 2") 8: print("> Wow it's matched to 8") # <-- here the same comparison will fail _: print("No match!") ` Output will be:

for i in array: 5 type of: 2 Is equal to 5 for i in array: 2 type of: 2 Is equal to 2 for i in array: 8 type of: 3 Is equal to 8 For n dictionary: 5 type of: 2 Wow it's matched to 5 For n dictionary: 2 type of: 2 Wow it's matched to 2 For n dictionary: 8 type of: 3 No match! `